Many portable devices, for example mobile telephones, are equipped with a display such as a glass or plastic display window for providing information to the user. Furthermore such display windows are now commonly used as touch sensitive inputs. The use of a touch sensitive input with the display has the advantage over a mechanical keypad in that the display may be configured to show a range of different inputs depending on the operating mode of the device. For example, in a first mode of operation the display may be enabled to enter a phone number by displaying a simple numeric keypad arrangement and in a second mode the display may be enabled for text input by displaying an alphanumeric display configuration such as a simulated Qwerty keyboard display arrangement. However such touchscreen inputs have a disadvantage with respect to mechanical keys in that the user does not experience the usual expected click or mechanical switch feedback to indicate that an input has been detected.
To attempt to overcome this some equipment has been provided with a mechanical or audible simulation of a key press. This feedback is known as haptic feedback when felt. Device-haptic feedback where the device is vibrated however requires significant current to operate in order to generate significant feedback force.
Furthermore some equipment can be equipped with so called singing display technology whereby the display technology can be moved by compressing a liquid crystal display layer between two layers of electrodes to generate an acoustic wave. However singing displays require specific display/electrode construction which leads to complex, expensive and inflexible displays and furthermore is limited to only some display technologies.
This application proceeds from the consideration that the provision of a flexible display driving mechanism capable of transferring the force provided by an actuator to the user by flexing and not significantly damping the force may provide both the physical and mechanical support for the display without unduly limiting the action of the display in producing tactile or haptic feedback and audio speaker functionality.
It is an aim of at least some embodiments of the invention to address one or more of these problems.